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Is Your Furnace as Efficient as You Think?

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The efficiency of a furnace is a key factor that directly impacts your home heating costs. A more efficient furnace is able to convert a higher percentage of fuel into heat, resulting in less wasted energy and lower utility bills. Investing in a high-efficiency furnace can lead to significant long-term cost savings and improved energy sustainability for homeowners. But is your furnace efficient?

How a Furnace Works

A furnace works by using fuel (like gas or oil) or electricity to heat a series of coils. Air from your home is drawn into the system, passed over these hot coils, and then distributed back into your house through ductwork. The process repeats until your home reaches the desired temperature. This simple yet efficient system ensures your home stays warm and comfortable throughout the colder months.

Assessing Your Home Furnace

Furnace efficiency ratings tell you how well your furnace converts fuel into heat. They matter because a higher rating means less wasted fuel and lower energy bills. It’s calculated as AFUE (Annual Fuel Utilization Efficiency), which is the ratio of the annual heat output of the furnace to the total annual fossil fuel energy it consumes. So, a 90 percent AFUE furnace means 90 percent of the energy in the fuel becomes heat for the home.

Energy Efficient Furnaces

Newer furnaces are more efficient due to advanced technology and design improvements. They often have higher AFUE ratings, indicating they convert a greater proportion of fuel into heat. Features like modulating gas valves and variable-speed blowers allow them to adjust output to meet real-time heating needs, reducing energy waste. Moreover, many new models are equipped with smart thermostats for optimal control, further enhancing energy efficiency and cost savings.

Determining Your Furnace’s Age

Finding your furnace’s manufacturing date is pretty simple. Usually, it’s on the serial number sticker – the first four digits often represent the week and year. So, “0303” would mean the third week of 2003. Knowing your furnace’s age is important because furnaces don’t get better with age. An old furnace can be less efficient, cost more to run, and may even need replacing.

Finding Your Furnaces AFUE Rating

To find out your furnace’s AFUE rating, you can check the EnergyGuide label, a yellow tag found on most appliances. If the label is not visible or missing, the AFUE rating may be included in the user manual or on the manufacturer’s website. HVAC technicians can also determine an AFUE by measuring a furnace’s heat output in BTU and its fuel input in BTU, then dividing the heat output by the fuel input.

What’s a Good Efficiency Rating?

For home appliances like furnaces, a good AFUE rating for a furnace typically falls between 80 and 98.5 percent. Standard furnaces today have ratings of around 83 percent, indicating they convert 83 percent of the fuel they consume into heat. Furnaces considered high-efficiency often have an AFUE rating higher than 90 percent, making them more energy-efficient, which can lead to lower energy costs and reduced carbon footprint. These HVAC units often have extra features that improve efficiency. Higher efficiency equals lower energy bills and less environmental impact making it a win-win.

Impact on Heating Bills

An inefficient furnace can really crank up your heating bills. If your old furnace has an AFUE of 60 percent, it means 40 percent of your energy is going straight up the chimney. Now imagine you switch to a modern furnace with a 95 percent AFUE. You’d save around 35% on your energy bill. If you’re spending $1000 a year on heating, that’s $350 back in your pocket. Efficiency pays off, literally.

Signs of an Old or Inefficient Furnace

Here are some common warning signs that your aging furnace might need to be upgraded:

  1. Increased Heating Bills: If your heating bills suddenly spike without a noticeable change in usage or weather, it could be a sign your furnace is operating inefficiently.
  2. Uneven Heating: Feeling cold spots around your house? Your furnace may not be distributing heat properly.
  3. Strange Noises: Furnaces should run quietly. Any banging, whining, or groaning could indicate mechanical problems.
  4. Frequent Repairs: If you’re calling the repair technician more often, it might be time for a new furnace.
  5. Age: Furnaces over 15 years old are likely nearing the end of their lifespan.

Addressing these signs early with an expert HVAC technician is crucial to prevent costly repairs or replacements down the line. Ignoring them can lead to a complete breakdown, leaving you with a cold home and an emergency fix bill. Plus, an inefficient furnace can significantly increase your energy bills. An HVAC technician can also help you decide if it is time to upgrade your furnace.

Furnace Efficiency Improvement

Regular maintenance of your furnace not only ensures its optimal function but also extends its lifespan. It helps detect potential issues early, saving you from costly repairs. Upgrades like installing a programmable thermostat can help manage heating more efficiently. Improve furnace efficiency by replacing filters regularly, insulating your home, and ensuring proper ventilation. If you think your furnace needs to be replaced, check with an HVAC expert to explore your new furnace installation options. Remember, an efficient furnace equals lower energy bills and a more comfortable home.

Single-Stage, Two-Stage, and Variable Speed Furnaces

When it comes to comfort and efficiency, the type of furnace you have matters. Single-stage, two-stage, and variable-speed furnaces have different energy efficiencies.

Single-Stage Furnaces

Single-stage furnaces are the most basic type of furnaces. They have only one stage of operation, meaning they’re either on or off. When turned on, they operate at 100% capacity, which can make them less energy-efficient and result in temperature fluctuations.

Two-Stage Furnaces

Two-stage furnaces have two stages of operation—low and high. The low stage operates at about 60-70 percent of the furnace’s full capacity, while the high stage operates at 100 percent. This allows for more consistent heating and improved energy efficiency as the furnace can adjust its output based on the temperature outside.

Variable Speed Furnaces

Variable-speed furnaces adjust both the heat output and the fan speed based on the needs of your home, providing the highest level of comfort and efficiency. The term “variable speed” refers to the furnace’s fan motor, which can move at different speeds to control the amount of heated air dispersed throughout your home. This results in more efficient heating and better air quality because it allows for continuous air circulation.

Determining Which Type of Furnace You Have

Determining the type of furnace you have can be done in a few ways:

  1. Check the User Manual: The easiest way is to refer to the user manual or product specifications. The type of furnace should be clearly stated.
  2. Model Number: Look for the model number on your furnace, usually found on a label inside the furnace cabinet. Then, search this number online or contact the manufacturer for information.
  3. Operation Noise and Heating Pattern: Single-stage furnaces tend to create noticeable temperature swings and noise as they turn on and off. Two-stage furnaces are quieter and provide more consistent heat. Variable speed furnaces are the quietest and provide the most even heating.
  4. Professional Inspection: If you’re still unsure, consider having an HVAC professional inspect your system. They can easily identify the type of furnace you have.

How an HVAC Expert Can Help

An HVAC expert can help assess a furnace’s efficiency in several ways:

  1. Inspecting the furnace: They will physically inspect the furnace for any signs of wear and tear that might affect its efficiency and help you know what type of furnace you have.
  2. Checking the AFUE rating: The Annual Fuel Utilization Efficiency (AFUE) rating measures how efficiently a furnace converts fuel into heat. A higher rating indicates better efficiency.
  3. Performing a combustion efficiency test: This test measures the amount of heat that’s actually being delivered to your home compared to the amount of fuel that you must supply to the furnace.
  4. Reviewing the system’s airflow: Proper airflow is critical for furnace efficiency. An HVAC expert can check for any obstructions or leaks in the ductwork.
  5. Providing maintenance tips: Regular maintenance can greatly improve a furnace’s efficiency. An HVAC expert can provide tips on proper furnace care and schedule regular tune-ups.

By assessing your furnace’s efficiency, an HVAC expert can identify potential issues and recommend solutions, helping you save money and improve comfort in your home.

The Path to Energy-Efficient Heating

Assessing furnace efficiency is a crucial step towards optimizing comfort and reducing energy costs in your home. It involves a simple procedure by our Jacobs Heating & Air Conditioning experts that can find potential issues early on. When it comes to any part of your heating system, you want a company that has the experience and knowledge to help you make informed decisions. Jacobs Heating & Air Conditioning experts are here to guide you.If you’re interested in high-efficiency furnace installation in your Portland, Oregon, or Vancouver, Washington home, contact Jacobs Heating and Air Conditioning to talk to an HVAC specialist about your options. No matter what you need, we’re always just a phone call away.

About the Author

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Amanda Jacobs, Internal Project Manager

Amanda Jacobs is an Internal Projects Manager and 3rd generation member of Jacobs Heating & Air Conditioning. She received her MBA from Seattle University and has worked for a leading HVAC training and consulting firm. When not talking HVAC on the Jacobs Blog, you can find her on the golf course or whipping up her famous vegan chili.